Externally-mounted imaging systems may be used on vehicles such as tactical military vehicles or vehicles used by emergency services to enhance a driver's viewing capabilities when operating in degraded seeing conditions such as darkness, fog, smoke or dust, or when operating in hazardous viewing conditions in which a driver has a restricted view from a protective vehicle. Examples include using an externally-mounted thermal imaging or image intensifying camera in degraded seeing conditions, or a video camera in hazardous conditions. These systems typically consist of a vehicle-mounted imaging camera for capturing live images and an active matrix liquid crystal display (LCD) to present the resulting images to the driver. For example, the camera may be an uncooled passive thermal imaging camera. FIG. 5 shows an example schematically in which a vehicle 45 has mounted upon its outer surface a camera 42 which produces a live feed of images to an image processor 43 which drives an internally-mounted LCD display screen 44 to display the live images to an occupant 5 (e.g. driver) of the vehicle.
Since the liquid crystal displays used in this set-up obscure the driver's view of the outside world, the driver must then rely entirely on the live camera image feed to control/steer the vehicle.
However, the output of such a LCD display typically presents an image generated at approximately 300 mm to 600 mm from the driver. This can result in kinetosis or motion sickness since relative motion between the driver and the LCD display gives a perception of movement which is not duplicated by the driver's vestibular system.
The invention aims to provide an improvement which may be used to address this situation and provide additional capabilities beyond those of a simple LCD display.